As a technology of video/audio transmission, there are a video/audio transmission system using MPEG compressed data based on the IEEE (Institute of Electrical and Electronics Engineers) 1394 standard, a component video transmission system of Y (luminance signal)/Pb (blue color difference signal)/Pr (red color difference signal) using a component terminal and a D video terminal, an optical digital audio transmission system in a digital audio format based on the IEC (International Electrotechnical Commission) 60958 standard and the IEC 61397 standard, and the like.
Furthermore, as an interface for high-speed transmission of digitized video signal between a computer main body and a display, the DVI (Digital Visual Interface) standard has been known.
The HDMI standard is a digital connection standard, which is a further improved version of the DVI standard, and an object thereof is to perform digital connection between an output device such as an STB and a display at home to meet the changes such as digitization of TV broadcast and a shift in a display device to a flat panel. The video/audio transmission in accordance with the HDMI standard is disclosed, for example, in the Patent Document 1.
In the HDMI, a function of transmitting audio signal and control signal is added to meet the requirement for TV uses. In the conventional connection between devices, a plurality of cables have been used for each signal of video, audio and control, however, since the HDMI standard needs only a single HDMI cable and the control signal is applicable to two-way transmission, it is also possible to operate the entire AV system (such as a home theater) with one remote controller by relaying the control signal to an output device such as an STB and a DVD player connected by the HDMI from a monitor.
Furthermore, in addition to the HDMI standard, there are the Display Port standard and the UDI (Unified Display Interface) standard as the improved version of the DVI standard. The UDI standard is different from the HDMI standard in terms of the fact that the UDI standard does not deal with audio signal, and the Display Port standard and the UDI standard are different from the HDMI standard in terms of the fact that the Display Port standard and the UDI standard are considered to perform the connections not only between devices but also within devices.
Meanwhile, a user often wants to perform not only display setting such as a character color and a font in the OSD (On Screen Display) display of a TV but also display setting such as a character color and a font in the OSD display of an AV device connected to the TV. Such display setting is suitable for preventing such a situation that a user can not know for which AV device the OSD operation is currently performed during setting.
In such a case, in the conventional technology for video/audio transmission as described above display setting is performed, by switching input to the TV to a target AV device, displaying a display setting screen of the AV device on a screen, and carrying out the operation using a remote controller (r/c) attached to the AV device.
Note that, the Patent Document 2 describes a technology of copying data regarding channel selection uniformly into a device to communicate with, and the Patent Document 3 describes a technology of copying various kinds of adjustment values uniformly between projectors.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-51547
Patent Document 2: Japanese Patent No. 2758174
Patent Document 3: Japanese Patent No. 3707433